babcock



Feb. 9, 1960 H. H. BABCOCK SUBMARINE SUCTION CLEANER Filed July 5, 1955 3 Sheets-Sheet 1 INVENTOR. #066 H BABZ'OCA 6441, Now: 24414.

4rr0rm9rs Feb. 9, 1960 H. H. BABCOCK SUBMARINE SUCTION CLEANER 3 Sheets-Sheet 2 Filed July 5, 1955 United States Patent SUBMARINE SUCTION CLEANER Hugh H. Babcock, Katonah, N .Y. Application July 5, 1955, Serial No. 519,961

13 Claims. (Cl. 151.7)

The present invention relates to cleaning apparatus adapted for the cleaning of the bottom surfaces of pools, tanks, and the like and more particularly relates to submarine suction cleaners.

Among the objects of the present invention are to provide effective and easily-controlled submersible suction cleaners for automatically cleaning the bottoms of tanks and the like, and particularly well adapted for use in swimming pools.

During use, swimming pools collect a large amount of dust, dirt and sediment which tends to build up a mucky silt layer on the floor of the pool. To maintain sanitary conditions and to have the water pleasant for swimming and prevent waders from stirring up clouds of silt, as they walk about, it is necessary thoroughly to clean the pool floor at frequent intervals.

Prior to this invention, two awkward and expensive systems have commonly been used for cleaning the bottom surfaces of swimming pools. For large municipal type pools, in many cases, divers are employed to clean the pool floor during periods when the pool is not in use. For home pools it has been customary to use long-handled suction nozzles which are swept along the pool floor by an operator standing near the edge of the pool. This is extremely tiring and often takes as long as six hours for cleaning an average small home pool. Moreover, these methods both involve the use of remote suction pumps with long lengths of suction hoses which are run under the water. Such suction hoses must be reinforced, as a practical matter to prevent collapse, and so are heavy, stiff, and hard to handle, and quite expensive.

Devices have been proposed for scrubbing pool floors, but these have not been adopted commercially because of their complexity and the need for complicated controls and guides. In certain cases remote pumps and suction hoses are utilized, with their attendant disadvantages. Some such prior devices involve the use of floats at the surface with complicated interconnections of cables and hoses extending between these floats and the cleaning device near the bottom.

Among the many advantages provided by the described submarine suction cleaner embodying the present invention are those resulting from the fact that the cleaner is automatic in operation and highly effective in cleaning a pool floor as it traverses back and forth. In this submarine cleaner the driving motor is directly associated with the cleaner which rolls on the pool floor.

Another advantage of the submarine suction cleaner described herein is the fact that the suction pump is directly mounted on the cleaner and is operated by the driving motor. Inasmuch as the liquid being discharged from the pump is at a pressure greater than the surrounding liquid in the tank, an ordinary highly flexible, light weight and inexpensive type pressure hose is enabled to be used as the discharge hose. The cleaner is automatically controlled to reverse the direction of its traverse or alternatively is steered by remote control from the surface.

ICC

A further advantage of the submarine cleaner described herein is its adjustable four-wheel steering which enables an accurate adjustment of the traversing of the cleaner as it moves back and forth across the bottom of the pool in a zig-zag course down the length thereof regardless of the pool Width. Thus, the desired amount of overlapping of the cleaning swaths is obtained regardless of pool size. The cleaner has a pair of intake openings extending completely across each end, and a controllable baffle structure closes up Whichever intake opening is at the rear end of the cleaner. When the cleaner reverses direction the baiile structure automatically reverses to open up the other intake and close the one which was open. Inside of the cleaner there are yieldable brushes which scrub the bottom of the pool to help loosen any silt which is sucked up through the pump. In the embodiment of the invention described these brushes are driven and reciprocate transversely of the cleaner body as it advances over the pool or tank floor.

In thesubmarine cleaner described the entire area beneath the cleaner body is subjected to a continuous suction action. Flexible skirts extend down from each side of the cleaner body against the pool floor, forming seals to prevent liquid from being drawn in from the sides. The intake openings are relatively narrow slots, one at each end, contiguous with the pool floor, and the rear one always is closed. Thus, the velocity of the liquid drawn into the body of the cleaner through the front intake opening is sufliciently high to erode and remove sediment, producing an effective scrubbing action. The cleaner body is supported on four wheels mounted on springs so as to accommodate undulations in the pool floor. All of the wheels are driven to obtain increased traction for driving the cleaner over the slopes found in the bottoms of some swimming pools and tanks and are steerable for producing the highly desirable traversing mentioned above. Control sensing elements are mounted at each end of the cleaner and also at the side, as described in detail, producing automatic control and traversing action.

In this specification and the accompanying drawings is shown and described a preferred embodiment of the present invention which consists in the features of construction, arrangements of parts, and elements as exemplified in this embodiment. However, it is to be understood that this described embodiment is not intended to be exhaustive nor limiting of the scope of the invention, but on the contrary is given for purposes of illustration in order that others skilled in the art may fully understand the invention and the principles thereof and the manner of applying the invention in practical use and modifying and adapting it in various forms, each as may be best suited to the conditions of a particular use.

The various features, aspects and objects of the present invention will be more fully understood from a consideration of this specification in conjunction with the drawings, in which:

Figure 1 is a partial perspective view illustrating the submersible cleaner in operation on the floor of the pool;

Figure 2 is a longitudinal vertical sectional view through the cleaner of Figure l;

Figure 3 is a top view partially broken away to show further details of the driving and controlling elements of the cleaner;

Figure 4 is a transverse vertical sectional View taken generally along the line 44 in Figure 3 looking up;

Figure 5 is a schematic circuit diagram of the control and power circuits;

Figure 6 is a cross sectional view of an improved buoyant hose; and

Figure 7 is a perspective view of this hose, showing the spaced chambers providing buoyancy.

In operation, the cleaner, generally indicated at 8, is lowered by means of the flexible hose 9 under the water 10 into an initial position, which is usually in one corner of the pool floor or other convenient position. Then the electric plug 11 on a waterproof power cable 12 is plugged into a suitable outlet and an on-off switch 14 in a manual control unit 15 is closed. This switch 14 is preferably of the toggle or similar type which remains closed until actuated into open position. An electric motor 16, which operates a pump 18 and drives the wheels 19, 20, 21, and 22, is located within the upper part of a waterproof casing 24 and is separated by a partition 26 (see Figure 2) from the pump chamber in the lower part of this casing. Electrical power is suppliedto the motor windings 28 through leads 29 and 30 ina four-wire cable 31, and, assuming that a control solenoid 32 is energized, the drive elements of the cleaner are in the respective conditions shown in Figure 2 and the cleaner is driven toward the left in Figure 2.

In certain pool or tank installations a fixed suction pump is already available nearby with suitable suction hose. Then, the motor 16 may be used as a drive motor for moving the cleaner with the end of this suction hose connected to the cleaner, and the automatic control and steering operations of the cleaner are used to great advantage. However, the described embodiment of the invention, which operates as a self-contained cleaner with a pressure-type discharge hose has many advantages for use in most installations and provides very desirable flexibility in operation. I In this illustrative embodiment of the invention the casing 24 has a lower rectangular flange 34 suitably secured as by bolts 36 down against a gasket 38 resting on top of the main housing 40 of the cleaner. This housing completely encloses the cleaner body on top and on all sides except for a central top port 42 communicating with the pump 18 and with a small clearance hole 44 through which extends a control link 46 pivotally coupled to the armature 48 of the solenoid 32. A pair of flexible skirts 50 (see also Figure 4) extend down from opposite sides of the housing 40 and form resilient seals with the poo] floor, thereby preventing any significant amount of liquid from entering the interior of the housing 40 from either side.

A pair of narrow intake openings 52 and 54, respectively, extend across either end of the cleaner contiguous with the pool floor. As the cleaner moves to the left the rear opening 54 is advantageously closed off by means of a controllable bafile structure including a resilient baffle 56 carried by a rockable cradle 58 explained in detail hereinafter. The other resilient baffie 60 is raised up by the cradle 58 to clear the front intake 52 through which the water is sucked with considerable velocity. Thus, any silt on the pool floor within or immediately ahead of the opening 52 is drawn up off of the pool floor and up into the interior of the housing 40 and then through the port 42 and through the pump 18 into the discharge hose 9 connected firmly to one side of the casing 24 as shown in Figures 3 and 4. The pump 18 is of the centrifugal type and includes an impeller secured to an extension of the motor shaft 61 with a plurality of impeller blades, two of which are indicated by dotted lines in Figure 2, and arranged to produce a large rate of flow out of a tangential discharge nipple 63 coupled to the hose 9. The water discharged from the upper end of the hose 9 may be thrown away, or in many cases is conveniently used to water grass or plants.

Where filtering equipment is' available, the water from the dischargehose 9 is filtered and returned to the pool.

To enhance the scrubbing action, a brush 62 extends across the width of the cleaner immediately behind the I opening 52. This brush is movably mounted by means of headed pins 65 loosely passing through slots 66 in a horizontal support bracket 67. The bristles are yieldingly urged against the pool floor by a plurality of compression springs 68 around the individual pins 65. A similar brush is mounted immediately inside of the other opening 56. There is considerable space between the two brackets supporting the brushes 62 and the tops of the brushes so that a large part of the intake flow advantageously passes upwardly ahead of each brush and over them as shown by the arrow 70. This produces an extremely effective scrubbing and suction action, removing substantially all dirt from the pool floor. The brushes are reciprocated by a drive linkage described below.

In certain instances a single brush extending across the width of the housing 40 near the center of the cleaner is used instead of the pair of brushes shown. But the arrangement as shown with each brush located just inside of the low intake port 52 or 54 is most effective. The sediment eroding action of the rapid intake flow through the port is combined with the scrubbing action of the brush which kicks up any of the dirt not lifted by the intake flow alone. The dirt is caught in the flow 70 and continues up to the pump.

Controllable drive mechanism '42 and is secured to a worm 74. This shaft 61 has its lower end journaled in a bearing 76 secured by a bracket 78 within the housing 40. The worm 74 drives a gear 80 fastened to a shaft 82 journaled in the bracket 78 and in a parallel bracket 84. Further speed reduction is provided by a small drive gear 86 fixed to this same shaft 82 and coupled through a shiftable idler gear 88 to a large drive gear 90 which is connected through a shaft 92 supported between these brackets to a chain drive sprocket 94. A chain 96 shown as a ladder-type chain of corrosion resistant wire which resists clogging, en gages this sprocket and runs around a pair of axle sprockets 98 and 100 fastened to the medial portions of the axles 102 and 104, respectively.

In reversing the direction of drive, the shiftable idler gear 88 is moved to an upper position where it engages a reversing idler 106 turning with the gear 86. This reversing is controlled by the solenoid 32 and by a compression spring 108 around its armature 48 bearing down against a retaining pin, as shown in Figure 2 biasing the armature toward its lower position. A waterproof shield 110 surrounds the lower end of the armature and this spring and thus prevents water from being sucked in through the clearance hole 44. When the solenoid 32 is tie-energized the spring 108 moves the armature down and pushes the control link 46 down to its lower position shown in dotted outline. The link 46 is connected to one end of a shift lever 111 pivotally supported on the shaft 92 with the shiftable idler 88 supported on the other end of this shaft so that is swings up to engage the reversing idler 106 when the solenoid is de-energized. This motion of the shift lever 111 also serves to control the steering mechanism as explained in detail further below.

In order successively to energize and de-energize the solenoid 32 automatically to reverse the cleaner 8 when it reaches opposite sides of the pool, a push rod is provided projecting beyond both ends of the cleaner and having suitable stop sleeves 122. For example, when the left end of this push rod (see Figure 2) strikes a pool wall it is pushed to the right which actuates a control arm 124 to close a waterproof switch 126. As shown, this is a mercury switch of a double-throw type.

The solenoid 32 is connected in circuit with this pushrod actuated switch 126 and with a double-throw control switch 127 in the hand control unit 15 in such a way that the direction of travel of the cleaner is reversed automatically by bumping a wall or other obstruction and can be reversed at will by actuating the switch 127.

The circuits for operating the solenoid 32 include a con? tact arm 128 in the switch 127 adapted to engage either a contact 129 connected to the wire 30 or a contact 130 connected to the wire 29. A wire 131 extends from this arm 128 to the cleaner chassis, and the circuit to one terminal of the solenoid 32 is completed through a jumper lead 132. Another lead 133 extends from the other terminal of the solenoid 32 to the center contact of the mercury switch 126. The other two contacts 134 and 135 of the switch 126 are connected to opposite sides of the motor winding 28. The cable 31 may include a fourth wire 129 for the purpose of electrically grounding the cleaner frame.

Thus, whenever the push rod is shifted, the energization of the solenoid 32 changes, i.e. it becomes energized, or becomes de-energized, as the case may be, and the cleaner reverses direction. Likewise, whenever the manual control switch 128 is flipped over, the cleaner reverses direction, regardless of its previous direction, and regardless of the position of the push rod 120.

In order to turn off the motor 16 automatically when the cleaner has passed back and forth across tank sufiicient times to traverse to the opposite end from its starting point, a sensing roller 136 (Figure 3) is horizontally mounted on a push rod 137 near one corner of the cleaner. The roller 136 projects from the side of the cleaner in the direction in which the steering mechanism, described hereinafter, causes the cleaner to traverse. A spring 138 biases the push rod 137 toward its outer position. When the cleaner reaches the far end of the pool, the rod 137 is depressed, actuating a waterproof switch 139 (see also Figure 5) to interrupt the circuit through the motor winding 28.

When the cleaner .is initially lowered into the pool, the side containing the sensing roller 136 is directed toward the opposite end of the pool. The roller 136 enables the cleaner as it nears the end of its run to move along closely adiacent to the end of the pool while the switch 139 is being depressed. As indicated at 140, a second sensing roller may be included in this side of the cleaner near the other corner for actuating a switch similar to switch 139 in the motor circuit to turn it off in case this corner of the cleaner is adjacent the wall of the pool or tank at the end of a run. The leads 132 and 133 are grouped in a waterproof sleeve 141 between the motor casing 24 and the top of the solenoid casing.

Instead of having the motor and solenoid casings waterproof, the pump and solenoid adapted to have water admitted therein, with the windings themselves suitably protected.

' Brash oscillating mechanism In order to oscillate the brushes 62 in opposite directions laterally at high speed, an eccentric cam 142 on the motor shaft extension 61 engages a small roller (Figure 3) on an arm 143, pivoted at one end to a fixed bracket 144 depending within the housing 40. The other end of the arm 143 is pivoted to a longitudinally movable rod 145 connected at each end through bell cranks 146 and short links 147 to tabs 148 on the tops of the respective brushes. A spring 149 holds the small roller in engagement with the cam 142.

In certain applications where a slower brush speed is desired,

Wheel support mechanism spectively, by a universal joint 156. Each wheel supports the cleaner by means of an L-shaped bracket 158 having a vertical leg outside of the respective wheel with the end of the associated axle stub journaled therein. A horizontal leg portion of each bracket 158 is secured by a pivot 159 to the respective ends of cross arms 160 or 162, respectively, associated with the axles 102 and 104 and parallel thereto. Each of these pivots 159 is located directly above the associated universal joint 156, whereby the wheels are enabled to be turned without any canting of the drive axles 102 or 104.

The cross arms 169 and 162 are centrally pivoted at 164 and 166, respectively, to a pair of transverse brackets 168 and 170, thus enabling the wheels to ride up and down with respect to the cleaner housing in order arms directly over the wheel pivot points 159. These springs provide substantially equal supporting forces to the four corners of the housing 40 during operation.

A certain degree of resilient damping support action is provided by the yieldable skirts 50 running along both Steering mechanism arcuate motions of the various parts. turn this tie lever, an adjustably positioned steering link 194' is connected between any one of a plurality of arcuately positioned holes 196 in a widened 186 and one arm of this bell crank lever is connected by a link 206 to the shift arm 111 immediately below the gear 88. Thus, as the shift arm 111 is moved at the end of each traverse to reverse the cleaner, the four wheels are turned slightly to produce the desired traversing of the cleaner. For small pools the steering link 194 is connected in one of the holes 196 closer to the pivot 188 cleaning swaths.

In arranging the internal mechanism as described the various parts are arranged to make the over-all height of the cleaner as small as possible and to keep the center of gravity low so the cleaner will resist overturning on steeply inclined pool or tank floors.

mean

Intake bafile mechanism The intake bafiles 56 and 58 are secured to opposite ends of a rockable cradle 58 having a fulcrum pin 210 at the mid point of opposite sides of the cleaner. When one of the resilient ba'files is lowered to block one of the intake openings the other bafiie is automatically raised to clear the other opening. To rock the cradle 58 about the fulcrum pins 210 as the wheels are turned and the cleaner is reversed, a pair of inclined links 212 and 214 (Figure 3) extend up at an angle from points on the cradle equally spaced on opposite sides of one of the pins 210. These inclined links are pivotally connected at their lower ends to the cradle and at their upper ends to the adjacent ends of the tie rods 182 and 184, respectively. As shown in Figure 3 the tie rod 184 is shifted to the left, thus depressing the baffle 56.

Among the many other advantages of the submarine suction cleaner described herein is that its effective efficient cleaning action reduces the time required for a person to clean a pool, thus also utilizing less water when it is discharged from the pool. If desired, the discharged water can be filtered and returned to the pool.

As shown in Figure 1, among the advantages of this submarine cleaner with the pump and pressure discharge is that ordinary lawn-type pressure hose 9 is used. It is relatively flexible and light in weight. The electric cable 31 is shown as conveniently taped to the hose at spaced points 216.

Improved buoyant hose An improved extruded plastic buoyant hose is shown in Figures 6 and 7. This hose has a generally figure 8 cross section with the larger tube 220 used to convey liquids or gases, as the case may be. In order to give added displacement and buoyancy, the smaller parallel tube 222 integrally connected to the tube 220 is filled with a suitable gas, usually air in spaced chambers 226. This tube 222 is pinched closed at spaced points 224 along its length to form the separate chambers 226.

This hose is manufactured by extruding a plastic tube through a cored die having an annular opening. Air or other suitable gas is introduced through the cored die into the tube and maintained at suitable pressure within the continuous tube to keep it from collapsing before the plastic cools. The tube is extruded onto a conveyor which carries the inflated tube away from the extruder while the plastic cools, normally under water sprays, at a considerable distance from the extruder.

There is a running seal roller having a rim approximately A; of an inch Wide which is positioned close to the extruder. This running seal roller is positioned sufficiently close to the extruder to engage the plastic tube before the plastic has cooled below the sealing temperature. narrow strip along the length of one side of the tube down and seals it against the other side of the tube which is supported on the conveyor, dividing the original tube at 221 into two smaller tubes 229 and 222 having a generally rounded B-shape. Projecting from one side of the running seal roller and extending parallel to the roller axis and located near the rim is a sealing lug which crushes spaced points on the tube 222 on each revolution of the running seal roller. This makes a series of equally spaced transverse seals 224 extending completely across the tube 222, forming a series of plastic buoyancy pockets 226 containing gas trapped therein.

The gas is held in the tube 220 by means of a pinch roller which rolls along the tube 220 squeezing it down against the conveyor. This pinch roller is spaced sufficiently far from the extrusion die so that the plastic has cooled well below the sealing temperature before being engaged thereby. The tube 220 springs back to its cylindrical shape after passing this pinch roller. In

This running seal roller continuously crushes a running seal 221 is made by a rollers engaging opposite sides of the originally extruded tube. Also, the tubes 220 and 222 can, in certain instances, be manufactured through the use of an extrusion die having a figure 8 cross section, without the use of the running seal roller. However, I prefer to use the running seal roller for it enables the use of standard cored circular or annular dies which are now in use for extruding plastic hose.

A controlled how of air or other suitable gas is introduced into the interior of the tube 222 from the extrusion die. The rate of this controlled flow is sutlicient to keep the tube 222 properly supported from Within toprevent its collapse during its passage from the extrusion die to the second pinching device. This controlled fiow supplies the gas which is successively trapped in the chambers 226 as the hose moves away from the extrusion die past the second pinching device and then on to the pinch rollers.

There are many advantages in using this type of buoyant hose with a submarine suction cleaner as described to keep the hose from dragging on the bottom of the pool behind the cleaner. In addition, this type of buoyant hose is adapted for use in refueling ships atsea. In certain applications this buoyant hose is adapted to be used as a buoyant conduit, and electric wires are run through the hose 220, which thereby provides an insulating, protective, waterproof covering as well as providing the desired buoyancy to float the conduit assembly.

The plastic used is a copolymer of vinyl chloride-vinyl acetate suitably plasticized with tricresyl phosphate or vinyl chloride and vinylidene chloride copolyrners suitably plasticized.

From the foregoing it will be understood that the embodiment of the present invention described above is well suited to provide the many advantages set forth, and since different embodiments may be made of this invention and as the apparatus herein described may be varied in various parts, all without departing from the scope of the invention, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense and that in certain instances, some of the features of the invention may be used without a corresponding use of other features, or without departing from the scope of the invention.

I claim:

1. A submarine suction cleaner including a body adapted to be submerged beneath the liquid in a tank for cleaning the bottom surface of the tank, supporting and reversible driving mechanism on the body for moving the body along the bottom surface of a tank, said reversible driving mechanism including sensing means at opposite ends of the body adapted to reverse direction after an obstacle has been engaged by the sensing means, said body having skirt means extending down along opposite sides closely adjacent to the bottom of the tank defining a suction chamber open at the bottom and extending beneath a major portion of the underside of the body and having an elongated intake opening extending across one end of the body contiguous with the bottom surface along which the body is moving and feeding into said suction chamber, said opening having a small height relative to its length, a continuous suction pump on said body, said pump having a suction inlet communicating with the interior of said suction chamber, and a pressuretype discharge hose connected to the discharge of said pump and adapted to extend from said cleaner out of a tank.

2. A submarine suction cleaner adapted to be sub merged beneath the liquid in a tank for cleaning the bottom surface of the tank comprising a run along the bottom surface of the tank and having driving mechanism which is reversible in operation, said reversible driving mechanism including sensing means at certain instances the pair of running seal body adapted tov opposite ends of the body adapted to reverse the direction after engaging an obstacle, said body having a substane cleaner forming a suction chamber beneath the cleaner within said housing, said suction chamber extending over a major portion of the underside of the cleaner, resilient nected to the discharge of said pump for removal of the liquid and dirt ings.

3. A submarine suction cleaner adapted to be submerged beneath the liquid in a lapping paths, a housing on said body closed in at the top and extending down on all sides to positions near the bottom surface of the tank to form a suction chamber,

tric motor coupled to said pump, a pressure type discharge hose connected to said pump, and a submersible electric cable connected to said motor.

4. A submarine suction cleaner adapted to be suband tanks and the like adapted to run in a pool for cleaning the pool floor comprising a body, two pairs of supporting wheels thereon, said wheels being mounted on stub axles which are pivotally connected to the body for steering, of said stub axles, tie

and a drive connection between said idler gear and said drive Wheel.

7. A submarine cleaner adapted to be submerged beneath the liquid in a tank for cleaning the bottom surface to be connected to a suitable a plurality of wheels 8. A submarine suction cleaner including a body adapted to be submerged beneath the liquid in a tank for bafile. means being coupled to said reversible driving mechanism and being operated in synchronism for closing the opening at the respect to the direction of drive means defining an intake opening effectively extending substantially across body closely adjacent to the bottom surface, a brush immediately inside of each opening and extending along the length of each openliquid on the bottom surface for cleaning the bottom surface comprising a body adapted to be submerged including a plurality of supporting and driving members, said body having a pair of resilient skirts extending down near the bottom on opposite sides of the body defining a suction chamber beneath the body which is exposed to and closely adjacent to the bottom surface of the tank with a pair of intake openings extending across opposite ends of the body feeding into said suction chamber and being adjacent the bottom, a submersible electric motor on said body for operating said driving members, an obstruction sensing means at each end of the body, a reversible drive control mechanism on said body responsive to said sensing means for reversing said driving members, a mechanical means for slightly changing the axis of movement of the body upon reversing direction, brush means inside of and closely adjacent to each opening and engaging the bottom so that the intake flow through each opening is up and over the adjacent brush, a submersible electric cable for energizing said motor, and a continuous suction pump on said body driven by said motor having a suction side communicating with the interior of said body, whereby a continuous suction is maintained in said suction chamber for increasing the traction of said supporting and driving members.

11. A submersible suction cleaner as claimed in claim including an on-off switch in circuit between said cable and said motor, and second obstruction sensing means at one side of the cleaner for actuating said switch.

12. A fully automatic suction cleaner for swimming pools and tanks and the like adapted to run back and forth along partially overlapping zig-zag paths beneath the liquid on the bottom surface for successively cleaning partially overlapping strip-areas of the bottom comprising a cleaner body adapted to be submerged and including a plurality of rotating driving members on the underside, a reversible driving mechanism on said body connected to said driving members and including a submersible electric motor, an obstruction sensing means at each end of the body, said reversible driving mechanism being responsive to actuation of said obstruction sensing means for reversing the direction of motion, a mechanical steering mechanism for changing slightly the angle of the path of motion of the cleaner upon each reversal of motion and for maintaining all of said driving members in alignment so as to steer the cleaner along straight lines at an angle to one another as it progresses back and forth, thereby following partially overlapping zig-zag paths over the bottom surface, means defining a pair of intake openings at the two ends of the cleaner extending across the full width of the cleaner generally perpendicular to the direction of travel, means for selectively opening the leading one of said intake openings in the direction of travel, a continuous suction pump on the cleaner body having its suction side communicating with said intake openings, and

discharge means connected to the outlet of said pump.

13. A fully automatic submersible suction cleaner for swimming pools and tanks and the like adapted to run back and forth beneath the liquid on the bottom surface for successively cleaning partially overlapping paths which progress across the bottom surface comprising a cleaner chassis adapted to be submerged and including revolvable members projecting down beneath the chassis and adapted to run along the bottom surface, reversible driving and steering mechanism on said chassis connected to said revolvable members and including a submersible electric motor, a submersible electric cable for energizing said motor, obstruction sensing means at opposite ends of the chassis, said reversible driving and steering mechanism being responsive to actuation of said obstruction sensing means for reversing the direction of motion and changing slightly the path of motion of the cleaner during reversal of direction and maintaining all of said revolvable menu bers in alignment so as to guide the cleaner along straight overlapping paths as it traverses back and forth, said cleaner chassis having a suction chamber closely adjacent to and exposed to the bottom surface, said suction chamher extending beneath a large part of the cleaner chassis and including skirts extending down on opposite sides of the chassis closely adjacent to the bottom surface, a continuous suction pump on said chassis having its intake communicating with the interior of said suction chamber for providing a continuous increased traction of said revolvable members, means defining a pair of intake openings at the two ends of the cleaner extending across the width of the cleaner and connected to the intake of the pump, and a flexible discharge hose connected to the discharge of said pump.

References Cited in the file of this patent UNITED STATES PATENTS 

